/**
 * Copyright 2007 The Apache Software Foundation
 *
 * Licensed to the Apache Software Foundation (ASF) under one
 * or more contributor license agreements.  See the NOTICE file
 * distributed with this work for additional information
 * regarding copyright ownership.  The ASF licenses this file
 * to you under the Apache License, Version 2.0 (the
 * "License"); you may not use this file except in compliance
 * with the License.  You may obtain a copy of the License at
 *
 *     http://www.apache.org/licenses/LICENSE-2.0
 *
 * Unless required by applicable law or agreed to in writing, software
 * distributed under the License is distributed on an "AS IS" BASIS,
 * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
 * See the License for the specific language governing permissions and
 * limitations under the License.
 */
package org.apache.hadoop.hbase;

import org.apache.hadoop.hbase.util.Addressing;

/**
 * Data structure to hold HRegionInfo and the address for the hosting
 * HRegionServer.  Immutable.  Comparable, but we compare the 'location' only:
 * i.e. the hostname and port, and *not* the regioninfo.  This means two
 * instances are the same if they refer to the same 'location' (the same
 * hostname and port), though they may be carrying different regions.
 */
public class HRegionLocation implements Comparable<HRegionLocation> {
	private final HRegionInfo regionInfo;
	private final String hostname;
	private final int port;
	// Cache of the 'toString' result.
	private String cachedString = null;
	// Cache of the hostname + port
	private String cachedHostnamePort;

	/**
	 * Constructor
	 * @param regionInfo the HRegionInfo for the region
	 * @param hostname Hostname
	 * @param port port
	 */
	public HRegionLocation(HRegionInfo regionInfo, final String hostname, final int port) {
		this.regionInfo = regionInfo;
		this.hostname = hostname;
		this.port = port;
	}

	/**
	 * @see java.lang.Object#toString()
	 */
	@Override
	public synchronized String toString() {
		if (this.cachedString == null) {
			this.cachedString = "region=" + this.regionInfo.getRegionNameAsString() + ", hostname=" + this.hostname + ", port="
					+ this.port;
		}
		return this.cachedString;
	}

	/**
	 * @see java.lang.Object#equals(java.lang.Object)
	 */
	@Override
	public boolean equals(Object o) {
		if (this == o) {
			return true;
		}
		if (o == null) {
			return false;
		}
		if (!(o instanceof HRegionLocation)) {
			return false;
		}
		return this.compareTo((HRegionLocation) o) == 0;
	}

	/**
	 * @see java.lang.Object#hashCode()
	 */
	@Override
	public int hashCode() {
		int result = this.hostname.hashCode();
		result ^= this.port;
		return result;
	}

	/** @return HRegionInfo */
	public HRegionInfo getRegionInfo() {
		return regionInfo;
	}

	/**
	 * Do not use!!! Creates a HServerAddress instance which will do a resolve.
	 * @return HServerAddress
	 * @deprecated Use {@link #getHostnamePort}
	 */
	public HServerAddress getServerAddress() {
		return new HServerAddress(this.hostname, this.port);
	}

	public String getHostname() {
		return this.hostname;
	}

	public int getPort() {
		return this.port;
	}

	/**
	 * @return String made of hostname and port formatted as per {@link Addressing#createHostAndPortStr(String, int)}
	 */
	public synchronized String getHostnamePort() {
		if (this.cachedHostnamePort == null) {
			this.cachedHostnamePort = Addressing.createHostAndPortStr(this.hostname, this.port);
		}
		return this.cachedHostnamePort;
	}

	//
	// Comparable
	//

	public int compareTo(HRegionLocation o) {
		int result = this.hostname.compareTo(o.getHostname());
		if (result != 0)
			return result;
		return this.port - o.getPort();
	}
}